Stairclimbing wheelchair



April 13, 1965 G. D. GRQGAN 3,178,193

STAIRCLIMBING WHEELCHAIR Filed NOV. 21, 1962 4 Sheets-Sheet 1 INVENTOR.

Wm W A afMZ April 13, 1965 G. D. GROGAN 3,178,193

STAIRCLIMBING WHEELCHAIR Filed Nov. 21, 1962 4 Sheets-Sheet 2 [8] I55 INVENTOR. 1 60m? Zimyam iii A ril 13, 1965 s. D. GROGAN 3,178,193

STAIRCLIMBING WHEELCHAIR Filed NOV. 21, 1962 4 Sheets-Sheet 3 INVENTOR.

6607276 19 'wgam Y United States Patent 3,178,193 STAECLIMBING Wl-EELCHAR George D. Grcgan, 330 S. High, Longview, Tex. Filed Nov. 21, 1962, Ser. No. 239,207 14 Claims. (Cl. 280-526) My invention relates generally to wheelchairs, and more particularly to wheelchairs that are adaptable for ascending stairs.

The usual type of wheelchair is adapted to move over a smooth surface which may or may not be level, but such a wheel chair is not readily adaptable to be operated by an occupant to ascend or descend stairs or steps unassistedly. An invalid person or patient who is confined to a conventional type wheelchair and who desires to ascend steps or stairs must wait upon the services of an attendant or some other person who will pull the wheelchair and occupant up the stairs. This is annoying and bothersome to both the patient and the attendant. Also, when a person otherwise normal but confined to a wheelchair moves about his community, he constantly encounters steps and stairs which he is unable to negotiate without assistance. In the prior art which I am aware, there has not been available a satisfactory wheelchair that is adaptable for use by an occupant thereof to move over smooth surfaces as Well as to ascend or descend steps and stairs unassistedly.

Accordingly it is the general object of the present invention to provide an improved wheelchair of a type that is adaptable for ascending or descending stairs as well as traveling on a smooth support surface.

Another object of the invention is to provide for a Wheelchair a wheel having grousers for use when ascending or descending steps and stairs.

Another object of the invention is to provide for a wheelchair a wheel having grousers that may be readily extended or retracted as desired.

Another object of the invention is to provide for a wheelchair a wheel having grousers that are weight hearing and suitable for ascending or descending stairs when extended, and non-weight bearing when retracted.

A further object of the invention is to provide a wheel chair that is quickly and readily adaptable to a form which can be easily actuated by an occupant thereof to ascend or descend steps and stairs.

Another object of the invention is to provide vehicle wheels having improved extendable and retractable grousers thereon.

More particularly, in accordance with one embodiment of the present invention, there is provided a wheelchair and side wheels therefor which have extendable and retractable grousers. The wheelchair may include a chair frame having a pair of outwardly extending axles, a caster-type adjustable front wheel and a pair of grousered side wheels mounted for rotation on the axles. Each side wheel may include a wheelframe having a hub and a plurality of grousers pivotally mounted on the frame adjacent the periphery thereof. Each grouser may comprise a pair of pivotally mounted arcuate channel-shaped grouser portions which are disposed generally in an endabutting manner when the grouser is extended. When the grousers are retracted, the arcuate portions are disposed in a folded mutually over-and-underlying arrangement, the overlying portions thereof presenting a rollable wheel periphery. The grouser portions may also have side or check plates that are similarly mutually overand-underlying. When the grousers are extended, the cheek plates and the arcuate plates together with the wheel frame form a circumferentially disposed cavity. A resilient distendable fluid container is disposed within the cavity, and when it is distended it also extends the grousers and supports the weight of the chair and the occupant thereof. The grousers are so arranged that a surface of each successive grouser is presented for contact with the next successive higher step or stair tread, as the occupant manipulates a mechanism to cause the grouser-extended wheels to rotate.

In accordance with another embodiment of the invention there may be provided a form of side wheel having a conventional type tire mounted on a rim which is fixed to the wheel frame. A plurality of grousers are mounted on the wheel frame adjacent the periphery thereof. Each grouser may include a stationary channel member fixed to the wheel frame and an arcuate channel structure which is pivotally connected adjacent one end of the stationary channel member. A fluid impervious membrane is disposed between and fixed to both of the channel structures so as to form an inflatable sac. en the sacs are inflated the pivotable arcuate member of the grouser is extended in such a manner that successive extended grousers engage the successive higher steps or stair treads when the wheels are actuated by an occupant in the chair.

In accordance with one aspect of the present invention, the grousers may be all connected to a common reservoir of compressible fluid under suihcient pressure to supply the grousers with requisite fluid pressure when extended, and with means for forcing the grouser fluid back into the reservoir as the grousers are retracted. Also, if desired, a non-compressible fiuid could be used, with means for forcing it from the reservoir to the grousers and vice versa.

While the present invention is herein presented as ap plied to a wheelchair, it is understood that in certain of its aspects, and particularly as to the grouser and grouser actuating mechanism, the invention may also be applied to other vehicles, particularly to self-propelled vehicles of a type which need additional traction under certain conditions.

For a further understanding of the invention and for further objects and advantages thereof, reference may now be made to the following description taken in conjunction With the accompanying drawings in which:

FIG. 1 is a schematic side elevational view of a wheelchair in accordance with a preferred embodiment of the invention, with portions thereof being omitted for clarification purposes;

FIG. 2 is a front elevational view of the device of FIG. 1, with some other portions thereof being omitted for clarification purposes;

FIG. 3 is a schematic perspective view of a wheelchair in accordance with a preferred embodiment of the invention, some portions thereof being omitted for clarification purposes;

. FIG. 4 is a schematic elevational view of one side of a wheel of the device of FIG. 1, the grousers thereof being in an extended operational position;

FIG. 5 is a schematic fragmentary view of a portion of the wheel of FIG. 4, the grousers thereof being in a retracted operational position;

FIG. 6 is a sectional view taken at line VI VI of FIG. 4;

FIG. 7 is a sectional view taken at line VII-VII of FIG. 5;

FIG. 8 is a schematic elevational view of a brake mechanism for the device of FIG. 1;

FIG. 9 is a schematic elevational view of the other side of the wheel opposite that of FIG. 4;

FIG. 10 is a sectional view taken at line X-X of FIG. 9;

FIG. 11 is a schematic side elevational view of a fragment of a wheel in accordance with another embodiment of the invention; and

FIG. 12 is a sectional view taken at line Xl1-XII of FIG. 11.

Referring to FIG. 1, the wheelchair 11 includes a main frame 13; a pair of side wheels 15, 17 (see FIG. 2); a front wheel assembly 19; and an intermediary wheel assembly 21. For convenient reference herein, the leftend of the Wheelchair, as viewed in FIG. 1, is considered as the front; the right end as the rear; the near side as the left side; and the far side as the right side.

The main frame 13 includes a system of tubular mem- :bers that are either welded or pin-connected together to form a right and a left side frame 23, 25 and a seat and a back structure 27, 29 respectively. Each side frame 23, 25 includes a vertical tubular member 31, the upper end of which extends substantially perpendicularly thereto and which is provided with a handle grip 33. A pair of horizontal spaced parallel tubular members 37, 39 are connected to the vertical members 31 and 35, the member 39 joining the member 31 preferably at the lower extremity thereof. A vertical tubular member 35 is disposed between the forward ends of members 37, 39. Another tubular member 41 is disposed intermediately both members 31, 35 and 37, 39 and in substantially parallel spaced relation to members 37, 39. A pair of short tubular members 43, 45 are joined perpendicularly to each other and are substantially perpendicular to members 31, 39 respectively. An axle 47, 49 is attached to each of the frames 23, 25 at the juncture of the members 31 and 39. The axles 47, 49 project outwardly in opposite directions and are substantially perpendicular to the planes of the respective side frames 23, 25. The relative positions of the tubular members 37, 39 and 41 are determined in that the tubular member 41 is at the level of the seat structure 27; the tubular member 39 is at the level of the axles 47, 49; and member 37 serves as an arm support and is disposed at a convenient height above the seat level. An arm rest 51, which is an elongated piece of wood, plastic, hard rubber or other suitable substance, is secured to the top surface of the tube 37 in any suitable manner.

A tubular member 53 is disposed midway between tubular members 41 and is substantially parallel thereto, but it is located below the level of the tubular member 39. Near each end of the member 53, there is a rod 55, 57 which is fixed to the tube 53 and projects vertically upward. A pair of sleeves 59, 61 and 63, 65 fit loosely on the tubular member 53. The sleeves 59, 61 are disposed on the tubular member 53 with one on each side of the rod 55, and in the same manner the sleeves 63, 65 are disposed on each side of the rod 57. A plurality of tubular members or rods 67, 69, 71, 73 connect the sleeves 59, 61, 63, 65 respectively, and other sleeves 75, 77, 79, 81 fitted loosely on the tubular members 41. A pair of tubular sleeves 83, 85 fit loosely and are reciprocable on the rods 55, 57 respectively. A pair of links 87, 89 are pivotally connected at the ends both to the tubes 67, 69 and to the tube 83 respectively. Likewise, another similar pair of links 91, 93 are pivotally connected both to the tubes 71, 73 and to the tube 85.

The seat 27 and the back 29 are constructed similarly; each including a plate-like structure 95, 97 which is disposed between the inner opposed surfaces of the tubes 41 and 31 respectively. A pair of sleeves 99, 101 fit loosely on the right side of tube 41 and are fixed to the edge of the seat plate 95 in any convenient manner. A pair of latches 103, which may be of any suitable type, are fixed to the .left hand edge of the plate 95 in any convenient manner. These latches 103 engage the tube 41 and maintain the plate 95 in a horizontal position Similarly, a pair of sleeves litfit loosely on the right side of the tube 31 and are fixed to the edge of the plate 97. Another pair of latches 193 are fixed to the left hand edge of the plate 97 and engage the tube 31, maintaining the plate 97 in a substantially vertical plane. A foam rubber cushion 167, or other suitable seat material, may be applied to both the seat and back plate structures 95, 97. If desired, the cushions 107, 109 may be attached to the plates 95, 97'by screws, bolts, or in any other suitable manner.

The front wheel assembly 19 includes a single castertype wheel 111 mounted for rotation in a forked frame 113 whichis pivotally mounted to swivel in the enlarged end 115 of a screw 117. The screw 117 threadedly enigages an internally threaded recess of a tube 118 having a hand crank 119 integrally formed on its upper end. The enlarged lower end of the tube 113 is rotatably received by a collar 121 loosely surrounding the screw 117 and supporting a pair of foot rests 123 and a yoke 125. The yoke 125 is connected to the front end of the tubular member 53 by a pin 127. The.

enlarged end 115 of the screw 117 is provided with an integrally formed tongue 129 projecting rearwardly.

The intermediate wheel assembly 21 includes a frame structure 131 and a plurality of V-belt pulleys 133 which are mounted on axles 135 journaled in the frame 131. The frame 13-1 comprises a pair of spaced parallel bars 135, 137 each having front and rear end portions that are bent angularly upward in the planes of the bars 135, 137. The front end portions of the bars 135, 137 are pivotally connected to the tongue 129 by a common.

bolt and nut fastener 139. The rear end portions of the bars 135, 137 are pivotally connected to the tubular member 53 at its rear end by a common bolt and nut fastener 141. A continuous V-type belt surrounds the end pulleys and is supported intermediately by the other pulley or pulleys for a purpose to be explained hereinafter.

The side wheels 15, 17 are similarly constructed except that wheel 15 is a right hand wheel and wheel 17 is a left hand Wheel. It sufiices, therefore, to describe only one side wheel. For convenience, the right side gimel 15 has been selected and is shown in PEG. 1 and Referring then to FIG. 4, and to FIG. 6 also, the side wheel 15 comprises a hollow cylindrical frame 147 and a plurality of pivotable grousers2l49 which are actuated and maintained. in an operative position by an inflatable resilient inner tube 151.

The Wheel frame 147 includes a pair of circular side plates 153, that are maitained in spaced parallel relation by a plurailty of radial diaphragm plates 157 and a plurality of concentric cylindrical plates 159, 161, 163 disposed between and perpendicular to the side plates 153, 155. The ends of the plate 163 are welded to the side plates 153, '155, or it may be attached thereto in any suitable manner. The tube 163 slidably fits on another tube 165, only a portion of which is shown in FIG. 6, but all of which is shown in FIG. 10 and which will be described more fully hereinafter. The plate 159 is preferably welded to the side plates 153, 155 near the outer periphery thereof; the distance along a radius being equal approximately to one-half the depth of the inner tube 151. The plate 161 is disposed in any convenient radial position between the plates 159 and 163. The diaphragm plates 157 are disposed radially between and perpendicular to both the side plates 153, 155 and the concentric cylindrical plates 159, 163. Each diaphragm plate 157 has a plurality of openings 166 above and below the plate 161. While not shown, the plate 161 has a plurality of similar openings in it. These openings 166 serve at least two purposes, one being to lighten the weight of the wheel structure by the Weight of the material removed; the other being to provide fluid communication throughout the several compartments of the frame 147. The frame 147 is, therefore, a fluid-tight reservoir structure.

Each of the grousers 149 includes a pair of pivotable arcuate U-shaped structures 167, 169, which cooperate with each other and with the inner tube 151. The cooperating arcuate structures-167, 169, together with the cylindrical plate 159 and the outer portions of the side plates 153, 155, form an enclosure extending around the wheel. Within this enclosure the inner tube 151 acts to support the structures 167, 169 in a weight-bearing capacity, as will be explained hereinafter. FIG. 4 illustrates the grousers 149 in an extended operative position and FIG. 5 illustrates the grousers 149 in a retracted operative position. The grouser structure 167 includes an arcuate plate 171 which is formed to an arc of the wheel having its center at the axle of the wheel. The grouser structure 169 includes, also, an arcuate plate 173 which is formed to an arc of the wheel 15 having its center at the axle thereof. The arcuate plate 171 extends from point A to point B and supports a section of rubber tread 175 which may be adhesively secured thereto or fixed thereto in any other suitable manner. The arcuate plate 173 extends from point C to point D and supports a section of rubber tread 177 that is secured thereto in the same manner as tread 175 is secured to plate 171.

Spaced parallel side or cheek plates 179, 181, and 133, 185 are fixed to the circumferential periphery of the plates 171, 173 respectively and depend therefrom. vVhen the grouser 149 is in the retracted operative position, as shown in FIG. 5, the side or check plates 183, 185 overlie the side plates 153, 155 respectively and are pivotally connected thereto by fasteners 187, 189. Similarly, the side or check plates 179, 181 of the plate 171 overlie the side or cheek plates 183, 185 and are pivotally connected to the side plates 153, 155 by fasteners 191, 193. Thus, the common fastener 189, for example, pivotally supports the overlying cheek plates 181 of one grouser structure and the cheek plate 185 of the adjacent grouser structure. In like manner, the common fastener 193 pivotally supports the cheek plate 181 of one grouser and the cheek plate 185 of the adjacent grouser. Each of the cheek plates 183, 185 is provided with an integral ear-like projection 195, 197 which supports a short pin 199, 261, the end of which travels in an arcuate groove 2433, 265 in the overlying cheek plates 183, 185. The arcuate groove 263, 265 is so shaped and so located that when the grousers are being retracted (by a mechanism described hereinafter), the arcuate plate 173 and the tread 177 afiixed thereto will fold beneath the arcuate plate 171. In the folded position the tread 1'73 lies contiguously along the under surface of the plate 171, as shown in FIGS. 5 and 7. The shape of the cheek plates 179, 181 and 183, 135 are such that, when all of the grousers are in the extended position, as shown in FIG. 4, the cheek plates 17%, 181 overlap the cheek plate 133, 185 and, together with the arcuate plates 159, 171, 173, form the walls of a cavity. This cavity is substantially filled by the inner tube 151 which, when inflated, is shaped to substantially conform to the cavity. The inner tube 151 may be made up of a plurality of such inflatable cavity-conforming portions, equal to the number of grousers 149.

A double ring gear 2%17 is affixed to the outer surface of the plate 155 so as to concentrically surround and be substantially coplanar with another single ring gear 209. The gear 209 is suitably fixed to a plate 211 which is attached to the outer end of the tube 165. The double ring gear 207 has teeth on both its outer and inner surface, while the single ring gear 209 has teeth only on its inner surface. The purpose of these gears 207, 209 will be described hereinafter.

FIG. 9 illustrates the outer side of the left side wheel 17, while FIG. 10 is a sectional view taken at line X-X. The tube 165, which is fixed at one end to the plate 211, is also fixed at the other end to a plate 213 that is substantially parallel to the plate 211. The plate 213 has a plurality of pins 215, 216 near its periphery which extend perpendicularly from the surface of the plate. The pins 215, 216 are disposed on two generally concentric circumferences; the pins 215 being nearer the center than the pins 216. The radii through pins 215 are displaced slightly angularly from the radii through the nearest pin 216. One end a flexible wire or cable 217 is attached to a pin 219 projecting from the corner of the side plate 179, and the other end of the wire or cable 217 is attached to one of the pins 215 on the inner circumference. Thus, each cable 217 is generally disposed angularly in a clockwise direction from a radius through the nearest pin 216, as shown in FIG. 9. The purpose of the cables 217 will be described hereinafter.

The tube is mated with the axle 49 and bears against a shoulder 221 thereof. A washer 223 and a nut 225 are applied to the free threaded end of the axle 45 to maintain re tube 165 and the wheel structure associated therewith in position on the axle.

A tube 227, having preferably a circular cross section, is formed in a cincle having a diameter somewhat less than the diameter of the side plate 153. The tube 227 is fixed and maintained in spaced parallel relation to the side plate 153 by a plurality of tubes 229, 2311 projecting perpendicularly therefrom. Each tube 229 communicates with the tube 227 and with one end of a flexible tube 231 disposed within the frame 147. The flexible tube 227 also communicates fluidly with the inner tube 151 within the grousers 149. A throttle-type valve 233 is located in each tube 229 to control the flow of fluid in the tube for a purpose to be explained hereinafter.

FIG. 8 illustrates an operating lever 235 which comprises a shank 2 37 and a brake mechanism. The shank 237 has a handle 241 fitted at one end and a pinion shaft 243 and a pinion 245 fixed to the other broadened end. A stub shaft (not shown) projects from the broadened end of the lever 235 opposite to the pinion shaft 24-3. A sleeve bearing 247 is mounted to the frame 13 at the common intersection of the tubular members 43, 45 and receives the stub shaft therein. A suitable fastener device 24 8 maintains the shaft (not shown) in the sleeve bearing 247. The sleeve bearing 247 is so located that when the shaft of the lever 235 is supported therein, the pinion 245 engages the inner teeth of the ring gear 267. The brake mechanism includes a pair of bars 249, 25 1 which are pivotally attached to the shank 237 at a common point by a pin 25 3. The other end of each bar 249, 25 1 is pivotally attached by pins 255, 257 to the apex of a pair of triangular plates 24?, 261. Each plate 259, 261 has a plurality of teeth 262 along the lower edge. The teeth 262 are of matching size and shape to the outer teeth 264 of the ring gear 207. The ends of a tension spring 263 are attached to the bars 249 and 251, by a pair of pins 265 and 267 respectively. The pins 265, 267 also pivotally fix the ends of a pair of rods 26 9, 271 respectively.

The upper ends of the rods 269, 271 are pivotally connected by a common pin 273 to a handle guard 275 which is pivotally connected by a pin 277 to the handle 241 adjacent its lower end. A bail 279 is pivotally connected to the handle 24d by a pin 28-1 and is disposed in such a manner that when the handle guard 275 is brought close to the handle 241, the bail embraces the guard and secures it in a locked position. In such a locked position, the teeth 262 do not engage the teeth 264 and the brake mechanism is disengaged. When the bail 279 is removed, the spring 263 urges the plates 259, 261 toward each other and the teeth 262 engage the teeth 264 and thus set and lock the brake mechanism 239.

Another lever 283 (see FIG. 10), which is similar to the lever 235, is provided with a shaft 285 and a pinion 287 fixedly mounted on the end of the shaft 285. A stub shaft (not shown) is fixed in axial alignment with the shaft 285 and extends oppositely thereto. The stub shaft is journaled in a sleeve bearing 289 which is mounted on a vance each side frame 23,25. The sleeve bearing 289 is 50 located that the pinion 287 engages the ring gear 2&9. The stub shaft and the lever are maintained in pivotable position by a fastener 290, which is similar to the fastener 248, or it may be secured in any other suitable manner.'

A suitable brake mechanism (not shown), such as the brake mechanism 239, may be attached to the lever 23 to lock and maintain it in any selected fixed position. The purpose of the lever 283 will be explained hereinafter. FIGS. I1 and 12 illustrate a modified form of a right side wheel 15:: showing among other things another embodiment of a grouser 14%. In general, the structure of the modified form of wheel 15a is substantially the same as the wheel 15 of FIG. 9, and so a detailed description of the wheel 15:: will not be necessary; only the major structural changes of the modified form will be described. The wheel 15a comprises a pair of circular side plates 291 and 293 which are maintained in spaced parallel relation by a plurality of radial diaphragm plates 295 and a plurality of concentric arcuate plates 161a, 163a, which are disposed between and perpendicular to the side plates 25 1, 293. The plate 293 is somewhat smaller in diameter than the plate 291. The peripheral edges of the plates 291, 293 are fixed perpendicularly to one edge each of plate rings 297, 299, which are concentric and extend toward each other. The free edges of the plate rings 297, 299 are fixed perpendicularly to an annular shaped plate 301, which is also disposed parallel to the plates 291, 293. Thus, there is provided essentially a circumferential notch in the periphery of wheel 15a. The diaphragms 295, of course, are similarly notched and are provided with openings 166a in the manner of a preferred embodiment. An ordinary bicycle tire 303 is mounted in the usual manner on a rim 395, which may be of wood, plastic, metal or any suitable material. The rim 305 and tire 303 are supported on the wheel frame structure by a web plate 387 which is fixed perpendicularly both to the rim 305 and the plate 297. V

The grousers 149a of wheel 150. include a channel structure 309 which is formed generally to the contour of the plate 299 and which is fixed and maintained in spaced parallel relation there-to by a pair of fasteners 3'11, 313. Another channel structure 3 1-5 is pivotally connected to the channel 309 by the common fastener 311. The bottom 317 of the channel 315 curves upwardly at the free end, as shown in FIG. 11. A section of rubber tread 177a,

which is generally similar to the tread 177, is applied to and secured to a portion of the bottom 317 by adhesive, or in any suitable manner. The tread 177a extends generally from the free extremity 3 19 to a point 321 along 1 the periphery of the channel 315 near the fastener 311. A piece of flexible non-prous material which is impenvious to fluids is secured along its edges to the upstanding flanges and the back of the channels 309, 315 so as to form a substantially fluid-tight sac 323. The sac 323 may be inflated by a fluid which is delivered to it via a tube 231a connected to a tube 227a; both of the tubes 231a and 227a being similar to the tubes 231 and 227 described hereinbe-fore. Similarly, a throttle-type valve 233a is conveniently mounted in each of the tubes 229a. supporting the tube 227a. A pin 2119a is fixed perpendicularly to each of the channels 315 near the free extermity 319 for the purpose of attaching one end of a wire or cable 217a. The other end of the wire or cable 217a is fixed to a pin 215a mounted in a plate 2 13a. The plate 213a and the pin 2 15a described hereinbefore are similar to the plate 213 and pin 2-15.

The wheel 15:2. may, of course, be mounted on an axle 49a and secured thereto by a nut 225a, or in the same manner as the wheel 15.

Now, in order to described the operation of the wheelchair 11, reference is made initially to FIGS. 1, 3 and 5.

The wheelchair 11 of FIG. 3 is normally supported on a floor or other supporting smooth surface by the two side wheels 15, 17 and the front caster-type wheel 111. The

grousers 149 of the side wheels are at that time retracted and the outer periphery of the wheels will have a circular contour that is similar to the fragmentary portion shown in FIG. 5. A person sitting in the wheelchair may in the usual manner grasp and apply a force to the tube 227 which causes the wheelchair and occupant to move over the door or supporting surface. The V-type belt of the intermediary wheel assembly 21 does not normally contact the floor or supporting surface.

When, in the course of moving from one place to another it is necessary to ascend steps or stairs, the occupant of a wheelchair of my invention may readily and effectively accomplish the purpose without assistance from any other person. In a preferred mode of operation, the occupant first places the wheelchair so that the axis of the wheels 15, 17, which is in the axles 49, is substantially near and parallel to the front edge or nosing 325 of the first stair tread. The front wheel will be away from the stairs and the occupant will be sitting in the chair with his own back toward the stairs. As mentioned hereinbefore, the space within the frame 147, which is bounded by the side plates 153, and the concentric plates 15'), 163, forms an air receiver tank. The volume and pressure of the air therein is suificient to inflate the inner tube 151' and maintain it in an inflated condition even during the stair ascending procedure to be described presently. After the chair has been oriented with respect to the stairs, the occupant manipulates one of the throttle-type valves 233 to an open position. Air flows from the tank space in the frame via tube 23% into the hand ring 227; thence it flows via the tube 229 into the flexible tube 231 and enters the inner tube 151, inflating it. The occupant then rolls the chair toward the stairs until one of the grouser treads 177 contacts the first stair tread 327 (see FIG. 9). The occupant then releases the bail 279 from the levers 235 and, while holding the guard 275 close to the handle 241, manipulates both of the levers 235, whereby the pinions 245 rotate. The pinions 245 cause the ring gears 207 and the wheels 15, 17, to which they are fixed, to rotate also. The pinions 245 are preferably provided with internal ratchet mechanism of any conventional type (not shown), or if desired, any well known ratchet arrangement may be used to prevent the pinions 245 from rotating in the backward direction. The ratchet mechanism should of course be reversible. The arcuate grouser 169 and the tread 177 are so shaped that during the rotation of the wheels 15, 17 the chair is raised a distance that is substantially equal to the height of the stair riser 329 (see FIG. 9). When the wheels 15, 17 have rotated until they bear on the ends of the treads 177 (see FIG. 1), the tread 177 of the next succeeding grouser 149 will then be in position to make contact with the nosing 325 and tread of the next higher stair. Now, in order to form a bridge between the nosings of successive stairs, the hand crank lid is manipulated to extend the screw 117. The front wheel 111 and the intermediary wheel assembly 21 then assume a position in which the locus of the wheel axis is substantially parallel to and spaced from a plane tangent to the stair nosings, about as shownin FIG. 1. It is clear, therefore, that the weight of the chair and occupant is supported by the treads 177, the V-type belt 145 and pulleys 133, and the front wheel 111. Thus, it is evident that the occupant of a wheelchair of my invention may expeditiously and unassistedly ascend stairs. To descend stairs, the procedure would simply be reversed.

In the event of any emergency, the safety brake mechanism may be readily and easily set. It is only necessary to release the handle guards 277 so that the spring 263 may bring the teeth 262 into engagement with the teeth 264. In this simple manner the wheels are locked and the chair will remain in a set position until the safety brake mechanism is purposefully released.

In a preferred embodiment of my invention, the levers 283 operate in guides (not shown) that are similar to the guides 329, 331 in which the levers 235 operate. Each of the guides 329, 331 is a pair of rods formed as a closedended loop, the plane of which is curved to the arc of a circle having a radius centered on the axle 49. The guides 329, 331 are fixed at one end to the tubular member 41 and fixed at the other end to a plate 333, which is fastened to and depends from the tubular members'37.

After climbing the stairs and reaching a smooth floor or other support surface, the grousers may be readily retracted so that a relatively smooth wheel perimeter is available for movement over a floor or support surface. The brake mechanism is set to lock the wheels in one position. The throttle-type valve 233 is opened and the levers 283 are made operat ve by releasing the bails from the handles. The levers 283 are manipulated simultaneously or one at a time, and the pinion 289 causes the ring gear 209 and the plate 213 to which it is connected to rotate in a counter clockwise direction, as viewed in FIG. 9. As the plate 213 rotates, the wires or cables 217 pull on the pins 219 and the arcuate grouser structure 167 pivots about the fastener 193. As explained hereinbefore, the cooperating grouser structure 169 folds beneath the structure 167. At the same time, the air in the inner tube 151 is forced via the tubing and valve back into the frame tank from where is came. The plate 213 is rotated until all of the grousers 149 are folded and the outer periphery appears as shown in FIG. 5, whereupon, the brake mech anism of the levers 233 is set to lock and maintain the grousers in the retracted position. The throttle-type Valve 233 may now be closed. It will be readily appreciated by those skilled in the art that the purpose of the two concentric circular rows of offset pins 215, 216 is to maintain each wire or cable free of the next succeeding cable. As the plate 213 rotates counterclockwise, as viewed in FIG. 9, the cables 217 bear against the pins 216 in the outer row, thus preventing one cable 217 from interfering with another cable 217.

After the grousers are retracted and the brake mechanism is set to lock them in the retracted position, the crank 119 is manipulated to retract the screw 117 and the front wheel assembly. The crank 119 may be manipulated until the wheelchair is substantially level or any other desirable position.

The preferred method of operating a wheelchair having wheels of the embodiment of FIG. 11 is essentially the same as described hereinbefore. In the embodiment of FIG. 11 the air flows into the handring 2279 (see FIG. 12) via the tube 229:: and the valve 233a. From the hand ring 227, the air flows via the tube 231a into each of the grousers 149a and infiates them to a weight supporting extended position. The procedure for ascending the stairs is similar to that described previously and may therefore be referred to. The procedure to retract the grousers 149a is likewise similar to the procedure described hereinbefore. It is to be noted that when grousers or the device of FIG. 11 are retracted, the grousers retract entirely within the circumferential notch of the side of the frame. The wheelchair and its occupant are supported then on the tires 363 and not on the grousers 149a, as they are in a preferred embodiment.

In a preferred embodiment of my invention the materials used are metal tubes and plates; rubber treads; foam rubber cushions; steel gears; plastic arm rests; and steel for the other miscellaneous equipment of the chair, except where noted. Of course, other suitable materials may be found and used as effectively as those I prefer. Of primary concern is suitability of material, strength and lightness of weight. In some applications, plastic may be substituted for the metal of many component pieces.

It should be apparent from the foregoing that I have provided a wheelchair that is an improvement over prior art wheelchairs of a type adaptable for ascending steps or stairs; that is readily adaptable by an occupant thereof to a form which can be unassistedly actuated by the occupant in ascending or descending stairs; that is readily transformable to a form for ascending stairs and to a form for traveling on a smooth support surface.

V/hile I have shown my invention in several forms, it will be obvious to those skilled in the art that it is not so limited, but is susceptible of various changes and modifications without departing from the spirit thereof.

I claim:

1. A grousered wheel apparatus comprising: a Wheel frame having a fluid-tight cavity therein with walls defined by a plurality of spaced parallel side plates of regular geometrical form and a plurality of spaced concentric cylindrical plates disposed between and fixed perpendicularly to said side plates, one said cylindrical plate forming a hub and one other cylindrical plate being disposed adjacent the periphery of said side plates; a plurality of grousers disposed around the periphery of said side plates, each said grouser comprising a first grouser portion including a first arcuate plate disposed tranversely of said side plates and a first pair of spaced parallel cheek plates fixed perpendicularly to the arcuate peripheral edges of said first arcuate plate, said check plates overlying the surfaces of said side plates and being pivotally connected thereto adjacent one end or" said first arcuate plate, and a second grouser portion including a second arcuate plate disposed transversely of said side plates and a second pair of spaced parallel cheek plates fixed perpendicularly to the arcuate peripheral edges of said second arcuate plate, said second pair of cheek plates overlying the cheek plates of an adjacent first grouser portion and being pivotally connected to said side plates adjacent one end of said second arcuate plate, the other ends of the said arcuate plates being in mutual end-abutting relation when said grouser is extended; a resilient distendable fluid container disposed around the perimeter of said wheel frame and within the walls of a space defined by the outer-most cylindrical plate, the said side plates and the inner surfaces of the mutually cooperative said first and second arcuate plates; a fluid in said cavity; means for injecting said fluid into said fluid container to distend same and to extend said grousers, said fluid container being substantially in contiguity with the walls of said space; a rotatable plate disposed concentrically with said hub and having a plurality of protuberances thereon; linkage means connecting each said protuberance and each said second grouser portion; means for rotating said rotatable plate to cause said linkage means to exert a force on and to retract each said grouser; means for simultaneously moving said fluid from said fluid container to said cavity as said grousers retract; and means for maintaining said grousers in such retracted form, said retracted grousers forming a rollable perimetrical surface of said wheel.

2. A grousered wheel apparatus comprising: a wheel frame including a pair of spaced parallel circular plates and a pair of concentric cylindrical plates disposed between and fixed to said circular plates, said plates forming the walls of a fluid-tight cavity with one said cylindrical plate forming a hub; a plurality of grousers arranged circumferentially around said frame, each said grouser including a first arcuate plate disposed transversely of and pivotally connected at one end to said circular plates adjacent the periphery thereof, and a second arcuate plate disposed transversely of and pivotally connected at one end to said circular plates adjacent the periphery thereof, the free ends of said arcuate plates being in substantially mutual end-adjacent relation when saidgrouse-r is extended, both said arcuate plates being substantially concentric with said circular plates; a resilient distendable fluid container surrounding said wheel frame intermediately the said arcuate plates and one said cylindrical plate; a fluid in said cavity; means for introducing said fluid into said fluid container to simultaneously extend said grousers; a rotatable plate disposed concentrically with said hub and having a plurality of protuberances therein; linkage means connecting each said protuberance and each said second grouser portion; means for rotating said rotatable plate to cause said linkage means to exert a force on and retract each said grouser, the said first arcuate plate pivoting into an underlying contiguous relation with said second arcuate plate, and with said second arcuate plates forming a rollable periphery of said wheel when said grousers are retracted; and means for simultaneously moving said fluid from said fluid container to said cavity as said grousers retract.

3. A grousered wheel apparatus comprising: a wheel frame having a fluid-tight cavity therein with walls defined by a plurality of spaced parallel side plates of regular geometrical form and a plurality of spaced concentric cylindrical plates disposed between and fixed perpendic ularly to said side plates, one said cylindrical plate forming a hub and one other cylindrical plate being adjacent the periphery of said side plates; a plurality of grousers disposed around the periphery of said side plates each said grouser comprising, a first grouser portion including a first arcuate plate disposed transversely of said side plate and a first pair of spaced parallel cheek plates fixed perpendicularly to the arcuate peripheral edges of said first arcuate plate, said cheek plates overlying the surfaces of said side plates and being pivotally connected thereto adjacent one end of said first arcuate plate, and a second grouser portion including a second arcuate plate disposed transversely of said side plates and a second pair of spaced parallel cheek plates fixed perpendicularly to the arcuate peripheral edges of said second arcuate plate, said second pair of check plates overlying the cheek plates of an adjacent first grouser portion and being pivotally connected to said side plates adjacent one end of said second arcuate plate, the other ends of the said arcuate plates being substantially in mutual end-abutting relation when said grouser is extended; a resilient distendable fluid container disposed around the perimeter of said wheel frame and within the walls of a space defined by the outermost cylindrical plate, the said side plates and the inner surfaces of the mutually cooperative said first and second arcuate plates; a fluid in said cavity; means for injecting said fluid into said fluid container to distend same and to extend said grousers, said fluid container being substantially in contiguity with the walls of said space; means for maintaining said fluid container in said distended condition; means for retracting said grousers and simultaneously moving said fluid from said fluid container to said cavity and contracting said container; and means for maintaining said grousers in retracted form, said retracted grousers forming a rollable perimetrical surface of said wheel.

4. A grousered wheel apparatus comprising: a wheel frame including a pair of spaced parallel circular plates and a pair of concentric cylindrical plates disposed between and fixed to said circular plates, said plates forming the walls of a fluid-tight cavity with one said cylindrical plate forming a hub; a plurality of grousers arranged circumferentially around said frame, each said grouser including a first arcuate plate disposed transversely of and pivotally connected at one end to said circular plates adjacent the periphery thereof,.and a second arouate plate disposed transversely of and pivotally connected at one end to said circular plates adjacent the periphery thereof, the free ends of said arcuate plates being in substantially mutually end-abutting relation when said grouser is extended, both said arcuate plates being substantially concentric with said circular plates; a resilent distendable fluid container surrounding said wheel frame intermediately the said arcuate plates and one cylindrical plate; a fluid in said cavity; means for injecting said fluid into said fiuid container to simultaneously extend said grousers; and means for retracting each of said grousers, with the said first arcuate plate pivoting into an underlying contiguous relation with said second arcuate plate and with said second arcuate plates forming a rollable periphery of said wheel when said grousers are retracted.

5. A grousered wheel apparatus comprising: a wheel frame having a hub and a fluid-tight cavity; a plurality of grousers disposed around the periphery of said frame, each said grouser including an articulated foldable frame structure pivotally connected at the opposite ends thereof to said wheel frame; a resilient distendable fluid container interposed contiguously between said wheel frame and said grouser frame structure; a fluid in said cavity; means for injecting said fluid into said fluid container to simultaneously extend said grousers from the periphery of said frame; means formaintaining said grousers in such extended form; means for retracting said grousers and simultaneously removing fluid from said container and contracting same; and means for maintaining said grousers in retracted form, said retracted grousers forming a rollable perimetrical surface of said wheel.

6. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting a pair of axles; a pair of grousered wheels mounted on said axles each said wheel comprising a wheel frame having a hub and a plurality of grousers disposed around the periphery of said frame, each said grouser including firstand second cooperative arcuate plate portions each pivotally connected to said frame and disposed in substantially mutually endabutting relation when said grouser is extended, said grousers being so arranged that when each said wheel is supported on a stair tread on the outer end of a first arcuate portion of one grouser, the second arcuate portion of an adjacent grouser is substantially in contact with the tread of the next higher stair; means for extending and maintaining said grousers in said extended position; and means for rotating each said wheel to bring each adjacent extended grouser thereof successively into engagement with successive stair treads to ascend said stairs.

7. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting a pair of axles; a pair of wheels mounted for rotation on said axles each said wheel comprising a wheel frame having a fluid-tight cavity therein and a rim encircling said frame and supported by said wheel frame; a plurality of distendable grousers disposed around the periphery of said wheel frame, each said grouser including a first channel member fixed to said wheel frame adjacent the periphery thereof, an arcuate second channel member pivotally connected at one end to one end of said first channel member and a flexible fluid-tight membrane disposed between and fixed to the respective adjacent sides and backs of said channel structures forming a fluid-tight sac; a fluid in said cavity; means for injecting said fluid into each said fluid-tight sac to distend same and extend said grouser outwardly from said rim; means for maintaining said grousers in such extended position; means for rotating said wheels to bring the extended grousers successively into engagement with successive stair treads; and means for retracting said grousers within the peripheral boundary of said rim.

8. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting a pair of outwardly extending axles; a pair of wheels mounted for rotation on said axles each said wheel comprising a wheel frame having an internal fluid-tight cavity and a rim encircling said frame and supported by said wheel frame; a plurality of distendable grousers disposed around the periphery of said wheel frame, each saidgrouser including a first channel member fixed to said Wheel frame adjacent the periphery thereof, an arcuate second channel member pivotally connected at one end to one end of said first channel member and a flexible fluid-tight membrane disposed between the respective adjacent sides of said channel structures and fixed thereto and to the backs of said channels forming a fluid-tight sac; a fluid inrsaid cavity; means for injecting said fluid into each said fluid-tight sac to distend same and extend said grouser outwardly 13 from said rim; means for maintaining said grousers in such extended position; a ring gear afiixed to said wheel frame and disposed concentrically with said axle; a pinion engaging said ring gear; and lever means operable by said occupant for rotating said pinion to cause said wheel to rotate and the wheelchair to ascend said stairs.

9. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting a pair of axles; a pair of grousered wheels mounted on said axles each said wheel comprising a wheel frame having a hub and a plurality of grousers disposed around the periphery of said frame, each said grouser including first and second cooperative arcuate plate portions pivotally connected to said frame and disposed in substantially mutually endabutting relation when said grouser is extended, said grousers being so arranged that when each said wheel is supported by the outer end of a first arcuate portion of one grouser, the second arcuate portion of an adjacent grouser is substantially in contact with the tread of the next higher stair; means for extending and maintaining said grousers in said extended position; a ring gear aflixed concentrically to each said wheel frame; a pinion engaging each said ring gear; and means operable by said occupant for rotating said pinions to cause said wheels to rotate and the wheelchair to ascend said stairs.

10. A grousered wheel comprising: a wheel frame having a hub; a plurality of grousers disposed around the periphery of said frame, each said grouser including an articulated foldable frame structure pivotally connected at the opposite ends thereof to said wheel frame; a resilient distendable fluid container interposed contiguously between said wheel frame and said grouser frame structure; means for injecting fluid into said fluid container to simultaneously extend said grousers from the periphery of said frame; means for mtaining said grousers in such extended form; means for retracting said grousers and simultaneously removing fluid from said container and contracting same; and means for maintaining said grousers in retracted form, said retracted grousers forming a rollable pen'metrical surface of said wheel.

11. A grousered wheel comprising: a wheel frame having a hub and a fluid-tight cavity; a plurality of grousers disposed around the periphery of said frame, each said grouser including a foldable frame structure pivotally connected adjacent an end thereof to said Wheel frame; a resilient distendable fluid container interposed contiguously between said wheel frame and said grouser frame structure; a fluid in said cavity; means for injecting said fluid into said fluid container to simultaneously extend said grousers from the periphery of said frame; means for maintaining said grousers in such extended form; means for retracting said grousers and simultaneously removing fluid from said container to said cavity and contracting said container; and means for maintaining said grousers in retracted form, said retracted grousers forming a rollable perirnetrical surface of said wheel.

12. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting a pair of axles; a pair of wheels mounted for rotation on said axles each said wheel comprising a wheel frame having a fluid-tight cavity therein and a rim encircling said frame and supported by said wheel frame; a plurality of distendable grousers disposed around the periphery of said wheel frame, each said i4 grouser including a first member fixed to said wheel frame adjacent the periphery thereof, a second member pivotally connected at one end to one end of said first member and a. flexible fluid-tight membrane disposed between and fixed to the respective adjacent sides of said members forming a fluid-tight sac; a fluid in said cavity; means for injecting said fluid into each said fluid-tight sac to distend same and extend sa-id grouser outwardly from said rim; means for maintaining said grousers in such extended position; means for rotating said wheels to bring the extended grousers successively into engagement with successive stair treads; and means for retracting said grousers within the peripheral boundary of said rim.

13. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheelchair comprising: a chair frame supporting apair of axles; a pair of grousered wheels mounted on said axles, each said wheel including a wheel frame having a hub; a plurality of grousers disposed around the periphery of same frame, each said grouser including an articulated foldable frame structure pivotally connected at the opposite ends thereof to said Wheel frame; a resilient distendable fluid container interposed contiguously between said wheel frame and said grouser frame structure; means for injecting fluid into said fluid container to simultaneously extend said grousers from the periphery of said frame; means for maintaining said grousers in such extended form; means for retracting said grousers and simultaneously removing fluid from said container and contracting same; and means for maintaining said grousers in retracted form; said retracted grousers forming a rollable perimetrical surface of said wheel.

14. A wheelchair adaptable for actuation by an occupant thereof to unassistedly ascend stairs, the wheechair comprising: a chair frame supporting a pair of axles; a pair of grousered wheels mounted on said axles, each said wheel including a frame having a hub and a fluid-tight cavity; a plurality of grousers disposed around the periphery of said frame, each said grouser including a foldable frame structure pivotally connected adjacent an end thereof to said wheel frame; a resilient distendable fluid container interposed contiguously between said wheel frame and said grouser frame structure; a fluid in said cavity; means for injecting said fluid into said fluid container to simultaneously extend said grousers from the periphery of said frame; means for maintaining said grousers in such extended form; means for retracting said grousers and simultaneously removing fluid from said container to said cavity and contracting said container; and means for maintaining said grousers in retracted form, said retracted grousers forming a rollable perimetrical surface of said wheel.

References Cited by the Examiner UNITED STATES PATENTS 2,214,311 9/40 Stevens 2805 .22 2,742,973 4/56 J ohannesen -8 2,765,199 10/56 Partin 30l47 FOREIGN PATENTS 78,898 4/ 19 Austria. 584,886 1/47 Great Britain.

ARTHUR L. LA POINT, Primary Examiner. 

6. A WHEELCHAIR ADAPTABLE FOR ACTUATION BY AN OCCUPANT THEREOF TO UNASSISTEDLY ASCEND STAIRS, THE WHEELCHAIR COMPRISING: A CHAIR FRAME SUPPORTING A PAIR OF AXLES; A PAIR OF GROUSERED WHEELS MOUNTED ON SAID AXLES EACH SAID WHEEL COMPRISING A WHEEL FRAME HAVING A HUB AND A PLURALITY OF GROUSERS DISPOSED AROUND THE PERIPHERY OF SAID FRAME, EACH SAID GROUSER INCLUDING FIRST AND SECOND COOPERATIVE ARCUATE PLATE PORTIONS EACH PIVOTALLY CONNECTED TO SAID FRAME AND DISPOSED IN SUBSTANTIALLY MUTUALLY ENDABUTTING RELATION WHEN SAID GROUSER IS EXTENDED, SAID GROUSERS BEING SO ARRANGED THAT WHEN EACH SAID WHEEL IS SUPPORTED ON A STAIR TREAD ON THE OUTER END OF A FIRST ARCUATE PORTION OF ONE GROUSER, THE SECOND ARCUATE PORTION OF AN ADJACENT GROUSER IS SUBSTANTIALLY IN CONTACT WITH THE TREAD OF THE NEXT HIGHER STAIR; MEANS FOR EXTENDING AND MAINTAINING SAID GROUSERS IN SAID EXTENDED POSITION; AND MEANS FOR ROTATING EACH SAID WHEEL TO BRING EACH ADJACENT EXTENDED GROUSER THEREOF SUCCESSIVELY INTO ENGAGEMENT WITH SUCCESSIVE STAIR TREADS TO ASCEND SAID STAIRS. 